Should I go out with my cousin's friend with benefits?

My cousin has this friend..and lately I was studying abroad for a few months, and we kept in contact (we used to talk every single day..). She didn’t really know this. He hinted to her but I never actually told her. Anyhow, when I came back we kinda hooked up. We didn’t tell my cousin about this. Things looked great, until I told my mum and she was concerned about my cousin, because she had the feeling that my cousin likes him. So I asked him and he said that they were just very close friends but nothing more. Mum asked my aunt, and turned out that my cousin is really keen on him, and that they sleep together and shit like that!! so I talked with this guy and we decided to put things on hold as we don’t want to hurt her. What kinda confuses me is that they’re not going out together, and that she always mentions other guys and stuff. Also, they went abroad with the rest of their friends lately, and she actually pulled other guys in front of him (showed me pics). So I’m like ‘does she really like him, or are they just ‘friends with benefits?!’ I really really like him, and lately we got talking again and plan on meeting up (we flirt so much when we talk). I really want to go out with him again..but dpn’t know if I’m doing the right thing. And last week my mum actually told me ‘hmm you know what, I think they’re just friends!!’ Another thing, he’s 8 years older than me (I’m 19, he’s 27).

cheers